Abstract

Degraded lignin compounds have been identified in Triassic age (about 200 million years) silicified wood from the Petrified Forest National Park in Arizona. The pyrolysis products from black carbonaceous samples include carbon dioxide, low-molecular-weight alkanes and alkenes, benzene, alkyl-substituted benzenes, phenol, cresol, xylenols, indenes, benzofurans, trimethylindanone, and naphthalenes. These compounds are also the primary pyrolyzates of modern lignin above 500°C.